Silicon最新文献

This study investigates the DC and RF characteristics of Quadruple Metal (QM) Inversion Mode (IM) and Junctionless (JL) Cylindrical Gate-All-Around (CGAA) Silicon Nanowire (SiNW) MOSFETs with a 3 nm gate length, using Silvaco ATLAS 3D TCAD and the Non-Equilibrium Green Function (NEGF) method with self-consistent Schrödinger-Poisson solutions. Key parameters analyzed include drain current (I_D), transconductance (g_m), transconductance generation factor (TGF), cut-off frequency (f_T), frequency transconductance product (FTP), transit time (τ), and total resistance (R_SD+CH) for a SiNW with a 3 nm diameter and 0.8 nm gate oxide. The impact of QM gate work function engineering is compared between IMQM and JLQM devices. JL devices are optimized for equivalent I_ON and V_TH as IM devices, achieving ~ 246.96 times and ~ 86.32 times lower I_OFF, respectively. QM gate variation reduces DIBL in both devices, with JL SiNW showing superior performance: DIBL (~ 75.42 mV/V), near-ideal subthreshold swing (~ 60 mV/dec), and high I_ON/I_OFF (~ 1.92 × 10¹¹), outperforming IM devices in SS, DIBL, I_ON/I_OFF, g_m, TGF, fT, τ, FTP, and R_SD+CH.

This study was aimed to optimize the efficiency of silica extraction from a silica-rich, natural solid waste perlite using dissolution–precipitation method. Four different mineral acids, namely, H₂SO₄, HCl, HNO₃ and HClO₄ were compared in precipitation step. The optimization process was accomplished using a proposed hybrid non dominated sorting genetic algorithm-II (NSGA-II) combined with back-propagation artificial neural network (BPANN) and response surface methodology (RSM). Various experimental parameters such as stirring temperature (40–120 ℃), time (0.5–6 h), NaOH concentration (2–8.5 M), and pH (2–7) were optimized using central composite design (CCD). In the proposed hybrid RSM-BPANN-NSGA-II model, projected data of BPANN was used as initial score and multiple regression equations of RSM were applied to develop two fitness functions maximum % yield and minimum time. An array of best-fit solutions was attained as Pareto front, and the final optimal design point was picked using technique for order preference by similarity to ideal solution (TOPSIS analysis). The optimized results were compared against Mean Absolute Error (MAE), Mean Square Error (MSE), and Root Mean Square Error (RMSE). In the optimization comparative study, proposed hybrid RSM-BPANN-NSGA-II model outperformed the other two models. Structure, morphology, and chemical bonding of silica extracted from perlite was studied utilizing different characterization techniques. XRD, FT-IR and UV–Visible DRS analysis depict the existence of amorphous Si–O-Si network while SEM–EDX results align with experimental data confirming that maximum % yield of silica (90.02) extraction was achieved by HCl precipitation. This study showed the relative superiority of optimized process parameters with higher silica % yield and reduced time.

This study investigates the combined effect of the cooling slope process and mold vibration on the morphology of primary silicon grains of A339 hypereutectic alloy. Subsequently, the study evaluates how different casting conditions influence the alloy’s density, porosity, and mechanical properties. The alloy was poured from the inclined plate with an angle of 45° and a length of 500 mm at two different pouring temperatures (580 °C and 590 °C) with and without mold vibration (30 Hz). For comparisons, conventional casting was done for the same process parameters. The microstructure, phase transformations and facture behaviour were analyzed using X-ray diffraction (XRD), optical microscopy, and scanning electron microscopy. The results indicate that the combination of melt shearing from the cooling slope and mold vibration significantly refines the primary and eutectic Si particles. When the pouring temperature decreased from 590 °C to 580 °C at specific mold vibration (30 Hz), the average grain size of primary Si particles decreased from 65 to 52 µm, and the average aspect ratio decreased from 3.23 to 2.98. The refined and uniformly distributed primary grains of Si (52 µm) (cooling slope process and mold vibration) resulted in improved mechanical properties, with the highest tensile strength (192 MPa), ductility (4.92%), hardness (82 BHN), density 2.73 gm/cm³ and lowest porosity 2.5% at 580 °C pouring temperature. Fracture behavior analysis reveals that fracture mode moves toward ductile from brittle in hypereutectic alloy. These findings demonstrate that the cooling slope process combined with mold vibration is an effective method for enhancing the microstructure and mechanical performance of A339 alloy.

The nanowire gate-all-around structure with the highest channel electrostatic integrity shows the best resistance to short channel effects and improved scaling compared to other multi-gate systems and capacity. We present a multistructure study of the impact of a gate-all-around nanowire tunnelling field on a transistor to enhance the drain current. This work describes ferroelectric nanowire tunnel field-effect transistors operating at V_DS = 0.5 V, well below the 20 mV/decade switching characteristics. Compared to traditional Nanowire tunnel field effect transistors, the suggested device performs better with a high I_ON-I_OFF ratio, lower subthreshold swing, and enhanced driving current. The proposed devices have a 1000 times better I_ON-I_OFF ratio than conventional NWTFET. The suggested devices are examined, including conductance, potential, energy band diagram, transfer and output properties, and other aspects for analog applications.

The manuscript conducts an extensive analysis of various spacer parameters on DC and analog characteristics of a novel Dopingless Nanosheet FET (DL-NSFET). The proposed study considers two types of spacers: single and dual spacers in symmetrical structure design. In a single spacer, Source/Drain side spacer are of the same kind of single-k dielectric material, and in a dual spacer, two vertically different-k spacer materials are used in the inner high-k configuration or in the inner low-k configuration. The effect of spacer materials having permittivity in the range of 1 to 22 and different spacer lengths in single and dual spacer configurations has been extensively studied in terms of analog and RF behavior. The high value of the drain current (2.39E-05 A), the high value of I_on/I_off ratio (2.39E + 09), lower SS (62.4 mV/Dec), lower DIBL (23.01 mV/V), higher g_m, lower g_ds, and higher gain is obtained with high-k (HfO₂) spacer making it suitable for analog and digital applications. The capacitance profile of the device is also increased with dielectric permittivity, resulting in low f_T and f_max. In dual spacer design, HfO₂ as inner spacer gives better analog behavior in terms of better I_off, I_on/I_off, SS and DIBL in comparison to SiO₂ as inner spacer material. Analog behavior of the device is improved with inner high-k spacer but RF behavior is better for inner low-k spacer.

This manuscript presents a simulation-based study of a vertically structured Tunnel Field-Effect Transistor photosensor designed for deep-ultraviolet detection in the wavelength range of 0.20–0.30 µm. The device performance is evaluated using different optical gate materials, specifically gallium oxide (Ga₂O₃) and zinc oxide (ZnO), both of which demonstrate enhanced optical response across the deep-UV spectrum. The Ga₂O₃-based device exhibits high sensitivity of 13.06 × 10⁵, a light-to-dark current ratio of 122.32 dB, and strong spectral sensitivity, while the ZnO-based counterpart achieves a superior responsivity of 1.95 × 10⁸ A/W and detectivity of 3.46 × 10¹³ Jones. The study further explores the effect of optical gate thickness on key performance metrics, identifying optimal conditions for improved sensitivity and light-to-dark current ratio. The impact of gate-to-source overlap is also examined, revealing its role in enhancing band-to-band tunneling efficiency and boosting photoresponse. Moreover, the influence of back gate extension is analyzed, showing a significant reduction in dark current and improved electrostatic control. Overall, this work offers valuable design insights into material selection and device architecture for optimizing the performance of vertically structured Tunnel field-effect transistor deep-ultraviolet photosensors.

Objective

The objective of the study was to investigate the impact of formulation variables on the physicochemical properties of silica-based nanoparticles as carriers for 5-Fluorouracil (5-FU).

Methods

Nanoparticles were synthesized via the sol–gel process involving the hydrolysis of tetraethyl orthosilicate (TEOS) alone or in combination with 3-aminopropyltriethoxysilane (APTES). Twenty-two formulations were prepared to explore the effects of precursor type, water volume, 5-FU amount, and pH of the hydrolysis medium on particle size (PS), polydispersity index (PDI), drug content (DC), and zeta potential (ZP) using statistical modeling by Partial Least Squares (PLS) multivariate analysis, Design of Experiments (DOE) and Gradient Boost Regressor (GBR). Stability studies in buffers simulating gastrointestinal conditions (pH 1, 4.5, and 7.4) were also performed.

Results

Nanoparticle sizes ranged from 48 to 1089 nm, PDI from 0.017 to 1, DC from 1.71 to 18.97 µg 5-FU/mg nanoparticles, with ZP values from -7.22 mV to 37.3 mV. Using the PLS, GBR and DOE, statistically significant formulation factors influencing nanoparticles` properties were identified. Stability studies conducted in buffers simulating gastrointestinal conditions demonstrated variations in PS (47 nm to 3333 nm), PDI (0.022 to 1), and ZP (-12.23 mV to 53.1 mV) and significant formulation factors were also identified via PLS, DOE and GBR modeling.

Conclusion

Silica nanoparticles with encapsulated 5-FU, were developed using three different modeling approaches through systematical examination of different formulation and process factors, and their impact on the nanoparticle physicochemical properties. Each model offers unique benefits and limitations, influencing its suitability for various stages in nanoparticle formulation.

To enhance silicon wafer surface quality and corrosion resistance during chemical mechanical polishing (CMP), this study develops a composite surfactant system combining nonionic AEO-9 and anionic ADBS. At an optimal AEO-9/ADBS molar ratio of 2:1, the formulation achieves low surface roughness (Ra = 0.135 (nm)), a high material removal rate (MRR = 198 (nm/min)), stable slurry dispersion, and peak corrosion inhibition efficiency of 93.3%. Synergistic effects at this ratio are confirmed by a negative interaction parameter ((beta) = − 1.90) and enhanced micellization. Adsorption between surfactant molecules and silicon wafer follows the Langmuir adsorption isotherm. Molecular dynamics simulations further reveal strong adsorption of surfactant molecules in a parallel orientation on the silicon surface, with a high binding energy of 337.2 (kJ/mol), which improves wetting and water retention. This work presents a strategy integrating corrosion inhibition with surface quality optimization in CMP slurries, providing molecular-level insights into surfactant-assisted protection for designing high-efficiency, low-defect slurries for advanced wafer fabrication.

This study presents a junctionless FinFET based quasi-nonvolatile memory (JL-FinFET QNVM) device with a silicon-on-insulator-like (SOI-like) structure and long retention time. In the JL-FinFET QNVM, the weak impact ionization mechanism is used to appropriately a induce weak impact ionization during the hold operation to generate holes continuously; this prevents the recombination of holes in the hold time. The sensing margin at both 300 and 358 K was 3.33 μA/μm when using the weak impact ionization mechanism in the proposed transistor. In particular, the proposed device showed an exceptionally lengthy retention time, with the quasi-nonvolatile characteristics exceeding 10² s regardless of the temperature. Additionally, the reliability of the proposed device was simulated by considering the grain boundary variation in polycrystalline silicon that was used for the SOI-like structure. The Shockley–Read–Hall recombination, hole density, and electron potential barrier were also analyzed to explore the memory state during the weak impact ionization mechanism.

This research presents the synthesis of biosilica from Tectonagrandis leaves and it’sincorporation into epoxy composites reinforced with Solanumprocumbens stem fiber, a unique material pairing not previously reportedwas fabricated using the traditional hand lay-up method. The developed composite PSB3, containing 2 vol.%biosilica, exhibited superior mechanical performance, achieving a tensile strength of 145.1 MPa, flexural strength of 189 MPa, impact strength of 4.7 J, and Shore-D hardness of 97. These improvements are attributed to optimal biosilica dispersion, which strengthened interfacial bonding and stress transfer within the matrix. The PSB4 composite, with 4 vol.%biosilica, recorded the highest wear resistance with a specific wear rate of 0.025 mm³/Nm and a coefficient of friction of 0.63, owing to the dense packing and rigidity of biosilica particles that reduced material removal. PSB4 also demonstrated the highest thermal conductivity (0.594 W/mK), attributed to the formation of efficient heat conduction pathways. In contrast, the neat epoxy specimen (P) showed the lowest water absorption (0.3%) due to it’s tightly crosslinked, hydrophobic structure. The novelty of this study lies in the valorization of Tectonagrandis leaf waste for biosilica production and the first-time integration of Solanumprocumbens stem fiber in epoxy composites, yielding a sustainable material with multifunctional enhancements. Overall, the proposed composites hold strong potential for marine, structural, biomedical, drone, and automotive applications.